Gas turbine engines include compressor, combustor, and turbine sections. Portions of a gas turbine engine are subject to high temperatures. In particular, the first sections of the turbine section are subject to such high temperatures that these sections are often cooled by directing relatively cool air through internal cooling passages.
U.S. Pat. No. 4,820,123, to K. Hall, describes a dirt removal means for air cooled blades of a gas turbine engine. The dirt removal means uses louvers stamped out of sheet metal that overlie the inlets of the blades' internal cooling passages. The louvers deflect dirt entrained in cooling air through a high velocity air stream and allow a cleaner portion of the cooling air to flow through the cooling passages of the blades.